I use a Sea & Sea optical glass port on a housing of another make via an adapter ring.

I buy my own photographic kit. Diving equipment manufacturers and diving services suppliers get even-handed treatment from me whether they choose to advertise in the publications I write for or not. All the equipment I get on loan is returned as soon as it is finished with.Did you know you can now get Diver Mag as an iPad/Android app?

Yeah, I've seen that review and whilst the reviewer is straight up about his involvement with the development of the port, I would like to garner further opinion on the port. If it's good, then great, I can get one at a good price. Otherwise I'll stick to an acrylic dome.

I bought one, but had to return it as there wasn't enough dome to place the Sigma 8-16 correctly without vignetting by the mount. The manufacturer would not provide the radius of the dome glass so I could calculate this before buying it. I bought a Nauticam 9" glass dome instead, which is what I should have done in the first place.